Electrorheological behavior of chitosan derivative suspensions

The electrorheological (ER) behavior of chitosan and chitosan phosphate sus pensions in silicone oil was investigated. Chitosan and chitosan phosphate suspensions showed a typical ER response (Bingham now behavior) upon applic ation of an electric field. However, chitosan phosphate suspension exhibite d excellent shear yield stress compared with chitosan suspension. The diffe rence in behavior results from the difference in the conductivity of the ch itosan and chitosan phosphate particles due to their degree of the polariza bility. The shear stress for chitosan and chitosan phosphate suspensions sh owed a linear dependence on the volume fraction of particles. The values of structure factor, A(s) obtained 1 and 3 similar to4 for chitosan and chito san phosphate suspensions and it may be due to the formation of single-row chains and multiple chains upon application of the electric field Throughto ut the experimental results, chitosan and chitosan phosphate suspensions we re shown to be an ER fluid.